1. Technology Field
The invention relates to a block management method. More particularly, the invention relates to a method for managing physical blocks of a rewritable non-volatile memory module, and a memory controller as well as a memory storage device using such method.
2. Description of Related Art
The characteristics of rewritable non-volatile memory include data non-volatility, low power consumption, small volume, and non-mechanical structure, etc; thus, the rewritable non-volatile memory is broadly applied to varied electronic devices. The rewritable non-volatile memory includes a plurality of physical blocks, and each of the physical blocks has a plurality of physical pages. Particularly, each physical block is the smallest erasing unit, and each physical page is the smallest programming (i.e., writing) unit.
When a storage device using the rewritable non-volatile memory (hereinafter “memory storage device”) is manufactured and formatted for the first time (i.e. the pre-formatting operation), the memory controller of the memory storage device conducts a disk scan among all the physical blocks of the rewritable non-volatile memory to identify normal physical blocks and damaged physical blocks. The normal physical blocks have priority for being grouped into the data area and the spare area by the memory controller, and the remaining physical blocks will be grouped into the replacement area. The physical blocks in the data area are used for storing data from the host system, the physical blocks in the spare area are used for alternating the physical blocks in the data area, and the physical blocks in the replacement area is used to replace the physical block damaged during the operation of the memory storage device.
Generally speaking, even normal physical blocks have different lifespan. Therefore, in the process of using the memory storage device, if the lifespan differences between the physical blocks are too huge, situation like data instability will easily arise.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.